Quantifying the absorption and reduced scattering coefficients of tissuelike turbid media over a broad spectral range with noncontact Fourier-transform hyperspectral imaging

Absorption (μa) and reduced scattering (μ′s) spectra of turbid media were quantified with a noncontact imaging approach based on a Fourier-transform interferometric imaging system (FTIIS). The FTIIS was used to collect hyperspectral images of the steady-state diffuse reflectance from turbid media. Spatially resolved reflectance data from Monte Carlo simulations were fitted to the recorded hyperspectral images to quantify (μaand μ′sspectra in the 550-850-nm region. A simple and effective calibration approach was introduced to account for the instrument response. With reflectance data that were close to and far from the source (0.5-6.5 mm), μaand μ′sof homogeneous, semi-infinite turbid phantoms with optical property ranges comparable with those of tissues were determined with an accuracy of ±7% and ±3%, respectively. Prediction accuracy for μaand μ′sdegraded to ±12% and ±4%, respectively, when only reflectance data close to the source (0.5-2.5 mm) were used. Results indicate that reflectance data close to and far from the source are necessary for optimal quantification of μaand μ′s. The spectral properties of μaand μ′svalues were used to determine the concentrations of absorbers and scatterers, respectively. Absorber and scatterer concentrations of two-chromophore turbid media were determined with an accuracy of ±5% and ±3%, respectively. © 2000 Optical Society of America.